/* PCSX2 - PS2 Emulator for PCs
* Copyright (C) 2002-2010 PCSX2 Dev Team
*
* PCSX2 is free software: you can redistribute it and/or modify it under the terms
* of the GNU Lesser General Public License as published by the Free Software Found-
* ation, either version 3 of the License, or (at your option) any later version.
*
* PCSX2 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
* without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
* PURPOSE. See the GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along with PCSX2.
* If not, see .
*/
#if !defined(_WIN32)
#include
#include
#include
#include
#include
#include
#include
#include "fmt/core.h"
#include "common/Align.h"
#include "common/Assertions.h"
#include "common/Console.h"
#include "common/General.h"
// Apple uses the MAP_ANON define instead of MAP_ANONYMOUS, but they mean
// the same thing.
#if defined(__APPLE__) && !defined(MAP_ANONYMOUS)
#define MAP_ANONYMOUS MAP_ANON
#endif
#include
#include
#include
#include
#ifndef __APPLE__
#include
#endif
static std::recursive_mutex s_exception_handler_mutex;
static PageFaultHandler s_exception_handler_callback;
static bool s_in_exception_handler;
#ifdef __APPLE__
static struct sigaction s_old_sigbus_action;
#else
static struct sigaction s_old_sigsegv_action;
#endif
static void CallExistingSignalHandler(int signal, siginfo_t* siginfo, void* ctx)
{
#ifdef __APPLE__
const struct sigaction& sa = s_old_sigbus_action;
#else
const struct sigaction& sa = s_old_sigsegv_action;
#endif
if (sa.sa_flags & SA_SIGINFO)
{
sa.sa_sigaction(signal, siginfo, ctx);
}
else if (sa.sa_handler == SIG_DFL)
{
// Re-raising the signal would just queue it, and since we'd restore the handler back to us,
// we'd end up right back here again. So just abort, because that's probably what it'd do anyway.
abort();
}
else if (sa.sa_handler != SIG_IGN)
{
sa.sa_handler(signal);
}
}
// Linux implementation of SIGSEGV handler. Bind it using sigaction().
static void SysPageFaultSignalFilter(int signal, siginfo_t* siginfo, void* ctx)
{
// Executing the handler concurrently from multiple threads wouldn't go down well.
std::unique_lock lock(s_exception_handler_mutex);
// Prevent recursive exception filtering.
if (s_in_exception_handler)
{
lock.unlock();
CallExistingSignalHandler(signal, siginfo, ctx);
return;
}
// Note: Use of stdio functions isn't safe here. Avoid console logs, assertions, file logs,
// or just about anything else useful. However, that's really only a concern if the signal
// occurred within those functions. The logging which we do only happens when the exception
// occurred within JIT code.
#if defined(__APPLE__) && defined(__x86_64__)
void* const exception_pc = reinterpret_cast(static_cast(ctx)->uc_mcontext->__ss.__rip);
#elif defined(__FreeBSD__) && defined(__x86_64__)
void* const exception_pc = reinterpret_cast(static_cast(ctx)->uc_mcontext.mc_rip);
#elif defined(__x86_64__)
void* const exception_pc = reinterpret_cast(static_cast(ctx)->uc_mcontext.gregs[REG_RIP]);
#else
void* const exception_pc = nullptr;
#endif
const PageFaultInfo pfi{(uptr)exception_pc, (uptr)siginfo->si_addr & ~__pagemask};
s_in_exception_handler = true;
const bool handled = s_exception_handler_callback(pfi);
s_in_exception_handler = false;
// Resumes execution right where we left off (re-executes instruction that caused the SIGSEGV).
if (handled)
return;
// Call old signal handler, which will likely dump core.
lock.unlock();
CallExistingSignalHandler(signal, siginfo, ctx);
}
bool HostSys::InstallPageFaultHandler(PageFaultHandler handler)
{
std::unique_lock lock(s_exception_handler_mutex);
pxAssertRel(!s_exception_handler_callback, "A page fault handler is already registered.");
if (!s_exception_handler_callback)
{
struct sigaction sa;
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_SIGINFO;
sa.sa_sigaction = SysPageFaultSignalFilter;
#ifdef __linux__
// Don't block the signal from executing recursively, we want to fire the original handler.
sa.sa_flags |= SA_NODEFER;
#endif
#ifdef __APPLE__
// MacOS uses SIGBUS for memory permission violations
if (sigaction(SIGBUS, &sa, &s_old_sigbus_action) != 0)
return false;
#else
if (sigaction(SIGSEGV, &sa, &s_old_sigsegv_action) != 0)
return false;
#endif
}
s_exception_handler_callback = handler;
return true;
}
void HostSys::RemovePageFaultHandler(PageFaultHandler handler)
{
std::unique_lock lock(s_exception_handler_mutex);
pxAssertRel(!s_exception_handler_callback || s_exception_handler_callback == handler,
"Not removing the same handler previously registered.");
if (!s_exception_handler_callback)
return;
s_exception_handler_callback = nullptr;
struct sigaction sa;
#ifdef __APPLE__
sigaction(SIGBUS, &s_old_sigbus_action, &sa);
#else
sigaction(SIGSEGV, &s_old_sigsegv_action, &sa);
#endif
}
static __ri uint LinuxProt(const PageProtectionMode& mode)
{
u32 lnxmode = 0;
if (mode.CanWrite())
lnxmode |= PROT_WRITE;
if (mode.CanRead())
lnxmode |= PROT_READ;
if (mode.CanExecute())
lnxmode |= PROT_EXEC | PROT_READ;
return lnxmode;
}
void* HostSys::Mmap(void* base, size_t size, const PageProtectionMode& mode)
{
pxAssertDev((size & (__pagesize - 1)) == 0, "Size is page aligned");
if (mode.IsNone())
return nullptr;
const u32 prot = LinuxProt(mode);
u32 flags = MAP_PRIVATE | MAP_ANONYMOUS;
if (base)
flags |= MAP_FIXED;
void* res = mmap(base, size, prot, flags, -1, 0);
if (res == MAP_FAILED)
return nullptr;
return res;
}
void HostSys::Munmap(void* base, size_t size)
{
if (!base)
return;
munmap((void*)base, size);
}
void HostSys::MemProtect(void* baseaddr, size_t size, const PageProtectionMode& mode)
{
pxAssertDev((size & (__pagesize - 1)) == 0, "Size is page aligned");
const u32 lnxmode = LinuxProt(mode);
const int result = mprotect(baseaddr, size, lnxmode);
if (result != 0)
pxFail("mprotect() failed");
}
std::string HostSys::GetFileMappingName(const char* prefix)
{
const unsigned pid = static_cast(getpid());
#if defined(__FreeBSD__)
// FreeBSD's shm_open(3) requires name to be absolute
return fmt::format("/tmp/{}_{}", prefix, pid);
#else
return fmt::format("{}_{}", prefix, pid);
#endif
}
void* HostSys::CreateSharedMemory(const char* name, size_t size)
{
const int fd = shm_open(name, O_CREAT | O_EXCL | O_RDWR, 0600);
if (fd < 0)
{
std::fprintf(stderr, "shm_open failed: %d\n", errno);
return nullptr;
}
// we're not going to be opening this mapping in other processes, so remove the file
shm_unlink(name);
// ensure it's the correct size
#if !defined(__APPLE__) && !defined(__FreeBSD__)
if (ftruncate64(fd, static_cast(size)) < 0)
#else
if (ftruncate(fd, static_cast(size)) < 0)
#endif
{
std::fprintf(stderr, "ftruncate64(%zu) failed: %d\n", size, errno);
return nullptr;
}
return reinterpret_cast(static_cast(fd));
}
void HostSys::DestroySharedMemory(void* ptr)
{
close(static_cast(reinterpret_cast(ptr)));
}
void* HostSys::MapSharedMemory(void* handle, size_t offset, void* baseaddr, size_t size, const PageProtectionMode& mode)
{
const uint lnxmode = LinuxProt(mode);
const int flags = (baseaddr != nullptr) ? (MAP_SHARED | MAP_FIXED) : MAP_SHARED;
void* ptr = mmap(baseaddr, size, lnxmode, flags, static_cast(reinterpret_cast(handle)), static_cast(offset));
if (ptr == MAP_FAILED)
return nullptr;
return ptr;
}
void HostSys::UnmapSharedMemory(void* baseaddr, size_t size)
{
if (mmap(baseaddr, size, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0) == MAP_FAILED)
pxFailRel("Failed to unmap shared memory");
}
SharedMemoryMappingArea::SharedMemoryMappingArea(u8* base_ptr, size_t size, size_t num_pages)
: m_base_ptr(base_ptr)
, m_size(size)
, m_num_pages(num_pages)
{
}
SharedMemoryMappingArea::~SharedMemoryMappingArea()
{
pxAssertRel(m_num_mappings == 0, "No mappings left");
if (munmap(m_base_ptr, m_size) != 0)
pxFailRel("Failed to release shared memory area");
}
std::unique_ptr SharedMemoryMappingArea::Create(size_t size)
{
pxAssertRel(Common::IsAlignedPow2(size, __pagesize), "Size is page aligned");
void* alloc = mmap(nullptr, size, PROT_NONE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
if (alloc == MAP_FAILED)
return nullptr;
return std::unique_ptr(new SharedMemoryMappingArea(static_cast(alloc), size, size / __pagesize));
}
u8* SharedMemoryMappingArea::Map(void* file_handle, size_t file_offset, void* map_base, size_t map_size, const PageProtectionMode& mode)
{
pxAssert(static_cast(map_base) >= m_base_ptr && static_cast(map_base) < (m_base_ptr + m_size));
const uint lnxmode = LinuxProt(mode);
void* const ptr = mmap(map_base, map_size, lnxmode, MAP_SHARED | MAP_FIXED,
static_cast(reinterpret_cast(file_handle)), static_cast(file_offset));
if (ptr == MAP_FAILED)
return nullptr;
m_num_mappings++;
return static_cast(ptr);
}
bool SharedMemoryMappingArea::Unmap(void* map_base, size_t map_size)
{
pxAssert(static_cast(map_base) >= m_base_ptr && static_cast(map_base) < (m_base_ptr + m_size));
if (mmap(map_base, map_size, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0) == MAP_FAILED)
return false;
m_num_mappings--;
return true;
}
#endif